The Planted Tank Forum banner

Water changes

11535 172
Ok I can't believe I am about to ask this question and I am sure there will be a good reason but I have kept fish for over 20 years and always carried out weekly waterchanges but I recently (2 months ago) set up my first fully flanted tank now I cycled the tank the first month using fishfood in a stocking the tank was cycled long before I finished my cycling scedule when first few fish went it it had 0 ammonia 0 nitrites and about 10 nitrate but once I put the fish in I removed the stocking and just added the food the fish needed to eat.

The water readings are now 0 ammonia 0 nitrite and almost 0 nitrates it is certainly less than 5 so as i add ferts to the water that will put nutrients in the water as well as CO2 and the plants are using up the nitrate. I am struggling to come up with a reason to change the water. I have seen a nitrate test as a good indicator of when to change the water previously but is this is still true in a planted tank with added ferts and CO2 if not why not.



The tank gets added ferts for the plants and the CO2 so what is the need for water changes if not to remove nitrate. The tank is open top and regularly gets topped up.
1 - 20 of 173 Posts

· Registered
Joined
·
2,677 Posts
Ok I can't believe I am about to ask this question and I am sure there will be a good reason but I have kept fish for over 20 years and always carried out weekly waterchanges but I recently (2 months ago) set up my first fully flanted tank now I cycled the tank the first month using fishfood in a stocking the tank was cycled long before I finished my cycling scedule when first few fish went it it had 0 ammonia 0 nitrites and about 10 nitrate but once I put the fish in I removed the stocking and just added the food the fish needed to eat.

The water readings are now 0 ammonia 0 nitrite and almost 0 nitrates it is certainly less than 5 so as i add ferts to the water that will put nutrients in the water as well as CO2 and the plants are using up the nitrate. I am struggling to come up with a reason to change the water. I have seen a nitrate test as a good indicator of when to change the water previously but is this is still true in a planted tank with added ferts and CO2 if not why not.



The tank gets added ferts for the plants and the CO2 so what is the need for water changes if not to remove nitrate.
Water changes will replace essential minerals plants and fish need that are not usually supplied via fertilizers (Ca and Mg for example).

Also, just because there is no NO3 present (the plants are using it up) does not mean there is no need for water changes, other organic compounds are decomposing in your water that will not contribute to the NO3 test.

Which NO3 test are you using? The API one is notorious for giving false readings if bottle 2 is not shaken for at least 1 minute and used immediately after shaking.
 

· Carpe Diem
Joined
·
7,566 Posts
This is actually a good question and I can argue both sides of the debate.

I believe that everything is situational and one size does not fit all.

As a personal example, I have hard water and am not too worried about Ca/Mg. The tank is at least 75% Java Fern with a bunch of floaters and Ambulia. Med to heavy load of guppies and some cories and I overfeed. Med light and co2 , blah blah blah. The tank had been running for about 15 years, with 3 - re-dos, the last one 3 years ago.

The end result is consistent 40 ppm N and 2 ppm P, pH of 6.7, tap is 7.4.

Sooo, why would I fertilize or do 50% weeekly water changes in that tank? I don't. Top off maybe once a week, 20-30% water change a month or two. Check TDS here and there.

We preach stability above all. What a 50% water change would do to that tank? Most likely nothing, except a higher water bill.

My point: don't blindly buy into somebody else's dogma. Instead think, observe, adapt.

A bare bottom Discus grow out tank? A rotala macrandra tank with 200++ PAR and white drop checker? Different beasts, different training.
 

· Registered
Joined
·
24 Posts
Discussion Starter · #4 ·
Water changes will replace essential minerals plants and fish need that are not usually supplied via fertilizers (Ca and Mg for example).

Also, just because there is no NO3 present (the plants are using it up) does not mean there is no need for water changes, other organic compounds are decomposing in your water that will not contribute to the NO3 test.

Which NO3 test are you using? The API one is notorious for giving false readings if bottle 2 is not shaken for at least 1 minute and used immediately after shaking.

I thought there would be something I do put a lot of water in in top up as it comes with being open top which would probably help with the Ca and Mg as I bet I replace 1/4 of the tank a week anyway (I have a Ca test somewhere but don't routinly test for it but will check it out) I do use API test kits and shake the bottle for a minute but also nutrafin but I had not thought about other organic compounds decomposing in the water that don't contribute to the nitrate test.

Obviously water changes are important in fishkeeping I will just have to decide how often but will play that one by ear
 

· Registered
Joined
·
24 Posts
Discussion Starter · #5 ·
This is actually a good question and I can argue both sides of the debate.

I believe that everything is situational and one size does not fit all.

As a personal example, I have hard water and am not too worried about Ca/Mg. The tank is at least 75% Java Fern with a bunch of floaters and Ambulia. Med to heavy load of guppies and some cories and I overfeed. Med light and co2 , blah blah blah. The tank had been running for about 15 years, with 3 - re-dos, the last one 3 years ago.

The end result is consistent 40 ppm N and 2 ppm P, pH of 6.7, tap is 7.4.

Sooo, why would I fertilize or do 50% weeekly water changes in that tank? I don't. Top off maybe once a week, 20-30% water change a month or two. Check TDS here and there.

We preach stability above all. What a 50% water change would do to that tank? Most likely nothing, except a higher water bill.

My point: don't blindly buy into somebody else's dogma. Instead think, observe, adapt.

A bare bottom Discus grow out tank? A rotala macrandra tank with 200++ PAR and white drop checker? Different beasts, different training.
Oh I will do some tests and the TDS is a good idea and I have a meter so really easy to do although adding ferts would increase TDS so unsure how that would work although may well need a graph, that will show how stable things are PH, ammonia, nitrite, nitrate and TDS I am only currently running the 6 foot tank and the 4 foot as I cut down but at one point I had 6 tanks


I just wanted to get other opinions on how to judge when a water change is needed
 

· Registered
Joined
·
1,418 Posts
Although we use nitrates as a measure of pollution, nitrates are merely the conversion of ammonia. But nitrates keep bad company as there are all sorts of other pollutants resulting from organic decomposition that we can't/don't measure for. The question we can't really answer is "Do plants absorb or adsorb all organic pollutants?".

It goes almost without saying that fast growing plants* consume nutrients (aka pollutants) and convert it into plant tissue...that we [may] eventually remove in trimmings. What we don't know is if this is complete enough to limit or replace routine periodic water changes that ensure ongoing 'fresh' water. (*slow growing plants do little to purify water)

In theory, I believe that fast growing (especially floating) plants can reduce the frequency and/or volume of required periodic water changes, but not eliminate them.
Like rain in nature, there really is no substitute for replacing [some] old tank water with fresh, pure water. The solution to pollution is dilution.

Footnote: We also need to consider our use of additives like ferts and consider that plants may not use all that we add. Also is the issue of required minerals that plants and fish use up from the water. Without a partial water change, how are these replenished?
 

· Registered
Joined
·
990 Posts
Ok I can't believe I am about to ask this question and I am sure there will be a good reason but I have kept fish for over 20 years and always carried out weekly waterchanges but I recently (2 months ago) set up my first fully flanted tank now I cycled the tank the first month using fishfood in a stocking the tank was cycled long before I finished my cycling scedule when first few fish went it it had 0 ammonia 0 nitrites and about 10 nitrate but once I put the fish in I removed the stocking and just added the food the fish needed to eat.

The water readings are now 0 ammonia 0 nitrite and almost 0 nitrates it is certainly less than 5 so as i add ferts to the water that will put nutrients in the water as well as CO2 and the plants are using up the nitrate. I am struggling to come up with a reason to change the water. I have seen a nitrate test as a good indicator of when to change the water previously but is this is still true in a planted tank with added ferts and CO2 if not why not.



The tank gets added ferts for the plants and the CO2 so what is the need for water changes if not to remove nitrate. The tank is open top and regularly gets topped up.
every tank is different and will have different water change frequency.

there is a made up rule of "50% water change per week" that has been treated like the 11th commandment floating around.

many blindly follow it

your question searches deeper for the true meaning of water change. I asked myself that same question after I skipped a week, and two, and three of water changes. When would I really need to change the water?

I pushed myself to 2-3 months with no water changes. I have heard examples of 6months, 9 months, a year with no water changes. wow.

I found my equilibrium at 30% water change once a month. mainly it helped suppress algae growth.

ultimately listen to the tank, and not a made up rule on the internets.
 

· Registered
Joined
·
1,073 Posts
I think the one thing missing in this great discussion is the fish.I personally do every other day on my discus tank and once a week on the planted tanks but for me it is the health of the fish more than the growth of the plants.I see a distinct improvement in the actions of the fish in my tanks after a water change so if your talking about a plant only or a very low stocked tank maybe you can go a lot longer without a water change.
 

· Registered
Joined
·
24 Posts
Discussion Starter · #10 ·
I think the one thing missing in this great discussion is the fish.I personally do every other day on my discus tank and once a week on the planted tanks but for me it is the health of the fish more than the growth of the plants.I see a distinct improvement in the actions of the fish in my tanks after a water change so if your talking about a plant only or a very low stocked tank maybe you can go a lot longer without a water change.

I didn't start this discussion to get out of water changes it is part of the hobby I did leave the fish out deliberately as I wanted to create a discussion on water changes and what we take out or put in by conducting them. Fish regardless of type produce waste obviously a heavy stocked tank would have more waste so need more changes than a lower stocked one.

There are downsides to water changes they can be stressful on tank inhabitants particularly large ones or in the winter when it is harder to equalise the temp so should be conducted but not excessively every other day sounds a lot unless you are changing only a small amount like 10% as small and often is better than the same amount further apart but every tank is different

The best way I ever found of doing them was a drip feed and waste pipe system as you never need to manually change the water, unfortunately, I do not have that on this tank but that is another discussion

Balance is the best so watching the tank and adapting the routine as I see fit is what I will be what I do of course ferts would be a double-edged sword as they put in the tank various things but there is likely to be things in them that are not used and would build up without enough changes .

Discus very obviously show when they are happy but many fish do not. So I really interested in the science of things as using nitrates to get an idea of how often a tank needs changing clearly isn't going to work on a fully planted tank as it does on one with no or minimal plants
 

· Banned
Joined
·
6,197 Posts
Having kept aquariums for 40 years, in my experience, the single best thing you can do for both fish and plants is regular water changes. This isn't something made up on the internet. It's just the plain truth.

Doesn't matter if it's low light, high light, or no light. Water changes are your friend and can prevent a whole host of potential problems.

The poster above who constantly advocates for very little or no water changes has killed more fish and grown more algae than seems possible. At one point his fish were literally jumping out of the tank to escape the filthy conditions. It's sad someone would try to persuade people to adopt a method that will almost certainly fail, or at minimum make their aquarium experience much more difficult and less rewarding.

Keep your water fresh and clean with regular water changes and your fish and plants will thank you.
 

· Registered
Joined
·
990 Posts
Having kept aquariums for 40 years, in my experience, the single best thing you can do for both fish and plants is regular water changes. This isn't something made up on the internet. It's just the plain truth.

Doesn't matter if it's low light, high light, or no light. Water changes are your friend and can prevent a whole host of potential problems.

The poster above who constantly advocates for very little or no water changes has killed more fish and grown more algae than seems possible. At one point his fish were literally jumping out of the tank to escape the filthy conditions. It's sad someone would try to persuade people to adopt a method that will almost certainly fail, or at minimum make their aquarium experience much more difficult and less rewarding.

Keep your water fresh and clean with regular water changes and your fish and plants will thank you.
I dumped 8 guppies into my newly started tank poisoned by high ammonia leached out of my ADA soil and they all jumped out over night

I thought it was because I didn't have a lid. I was less than 1 month into the hobby. I didn't know!

we all make mistakes, but we learn from them.

I don't appreciate you bashing on me all the time. can you please stop?
 

· Registered
Joined
·
209 Posts
At the Expense of the fish . Do some research . I will only do a fish less cycle now. It has taken 30+ days to complete . Its called patience . Not I dumped IntotheWRX into a lethal concoction of ammonia and nitrite he and he jumped out to his death . R.I.P.
 

· Registered
Joined
·
24 Posts
Discussion Starter · #14 ·
Guys let's not turn this debate into a slanging match we all know water changes are important and for the record, no poster is likely to persuade me to do anything but I like to get opinions from others I have kept fish for 25 years and can't remember the last time I lost a fish. The usual reasons for changing water is to get rid of nitrate clearly if there is no nitrate or the tap water has a higher nitrate level than the tank there could be reasons to go longer between changed than a week (I have no idea what the nitrate level is in my tap water but would not be surprised if it is higher) but there could be reasons not to as well so it is an interesting subject to discuss

Now I realise some of you may do a thing one way and be convinced this is the correct way but I don't want posters bickering and ending up derailing what could be a interesting debate.
 

· Banned
Joined
·
6,197 Posts
Now I realise some of you may do a thing one way and be convinced this is the correct way but I don't want posters bickering and ending up derailing what could be a interesting debate.
I see you are new here, and I believe your intentions are good.

What you may not know is that this topic typically does not end well. It's been brought up more times than you can imagine. A few years back there were some serious water change wars here.

And the poster above spent so much time advocating that no one should ever change their water, that he was banned from this board for awhile.

And I do agree it can be an interesting debate. The issue I have is that for the vast majority of people, water changes can be the difference between success and failure.

And that is not to say there aren't special circumstances where one could be successful without water changes, but that is in a very unique environment, and not for the average hobbyist.

Personally I have very rarely seen anyone be successful with a little or no water change schedule for any length of time. And most of the posters who advocate for it don't post any pictures of their tanks. You figure out why.
 

· Carpe Diem
Joined
·
7,566 Posts
Having kept aquariums for 40 years, in my experience, the single best thing you can do for both fish and plants is regular water changes. This isn't something made up on the internet. It's just the plain truth.

Doesn't matter if it's low light, high light, or no light. Water changes are your friend and can prevent a whole host of potential problems.
If I understand the original context of the post, the question is whether established best practices still hold in the changing world. I welcome such topics as they drive us to retain what is good and replace what is outdated. The plain truth might be evident to some, but not the others: the Earth was flat not that long ago.

Alright, here is one of my threads on my definition of natural tanks. Hopefully a 3+ year life span of that tank is good enough. Post 11 is the start of my filtration musings.

http://www.plantedtank.net/forums/1...low-cube-riparium-bunch-fibs-honest-lies.html

Bump: Plus a picture showing that we can swing to the other extreme.
 

· Registered
Joined
·
1,418 Posts
There are downsides to water changes they can be stressful on tank inhabitants particularly large ones or in the winter when it is harder to equalise the temp so should be conducted but not excessively every other day sounds a lot unless you are changing only a small amount like 10% as small and often is better than the same amount further apart but every tank is different
Actually decreasing the amount of pollution in a tank with a partial water change is not stressful - it's like a rain in nature. When I do water changes the fish seem invigorated. But yes, the change water needs to at least be close to tank water temperature.

The best way I ever found of doing them was a drip feed and waste pipe system as you never need to manually change the water, unfortunately, I do not have that on this tank but that is another discussion
The trouble with a drip system is that some new water typically goes out with the old.
Drip systems somewhat flatten the bell shape curve of pollution buildup and slightly extend the duration before a necessary WC, but are not a good substitute long term.

Balance is the best so watching the tank and adapting the routine as I see fit is what I will be what I do of course ferts would be a double-edged sword as they put in the tank various things but there is likely to be things in them that are not used and would build up without enough changes .
The trouble is we can't really see how increased pollution is affecting the long term health of the stock. Folks that push it think their fish are just fine and live an average life span...but what if with increased water changes where the water is more pure caused the same fish to live twice as long?!

Discus very obviously show when they are happy but many fish do not. So I really interested in the science of things as using nitrates to get an idea of how often a tank needs changing clearly isn't going to work on a fully planted tank as it does on one with no or minimal plants
As I mentioned previously, nitrates is merely one aspect of the pollution. You don't startup a new tank with dirty water, so how best do we maintain the purest possible water?....the answer is a routine partial water change. The frequency and volume may be somewhat flexible, but frequent and more will always trump infrequent and less.
 

· Registered
Joined
·
24 Posts
Discussion Starter · #18 ·
I see you are new here, and I believe your intentions are good.

What you may not know is that this topic typically does not end well. It's been brought up more times than you can imagine. A few years back there were some serious water change wars here.

And the poster above spent so much time advocating that no one should ever change their water, that he was banned from this board for awhile.

And I do agree it can be an interesting debate. The issue I have is that for the vast majority of people, water changes can be the difference between success and failure.

And that is not to say there aren't special circumstances where one could be successful without water changes, but that is in a very unique environment, and not for the average hobbyist.

Personally I have very rarely seen anyone be successful with a little or no water change schedule for any length of time. And most of the posters who advocate for it don't post any pictures of their tanks. You figure out why.
It is a shame there has been water change wars that can be a problem with internet forums, unfortunately. I would never say you never need to change the water that is a recipe for disaster and I agree the tank would need a very good balance to minimise them. Most aquariums are also overstocked due to modern equipment being very good the filter can often handle what is still an overstocked tank. Which obviously increases the need for water changed. Certainly, for the average hobbyist weekly water changes are essential. Particularly as many do not know how to read the tank.

One of my pet hates is fish store employees giving bad advice in order to make sales and have much to their annoyance saved many a newbie money and problems by speaking to the customer or victim if I got the chance. The last one was filter sponges the employee was insisting new sponges were needed every month and new carbon every week I explained the use of carbon to them and why if they chose to use it, it needs replacing but recommended they just used another media instead and told them there was no need to replace the sponges at all unless they were falling apart they just needed cleaning in tank not tap water but would never recommend not doing partial water changes to anyone

When I find a new LFS I go in and play the newbie just to see what advice they are giving out as it really gives you a good idea of how they behave (oscar be fine in a 10 gallon anyone) the LFS I most regularly spend money at and have for years is a small business but he basically told it like it is and did not try to sell any unnecessary products and said when stuff would not be worth buying. Over the years I have spent thousands there and even get a 10% discount on purchases because he gave me a card but I am getting off the subject.

It does seem unforseen chemical facts I was hoping to get from this discussion are not going to happen but as the subject has been raised I will just observe the tank and follow my gut to when changes are needed on this tank It would never be longer than a month but it may be above a week we will see what the tank tells me.
 

· Registered
Joined
·
24 Posts
Discussion Starter · #19 ·
Actually decreasing the amount of pollution in a tank with a partial water change is not stressful - it's like a rain in nature. When I do water changes the fish seem invigorated. But yes, the change water needs to at least be close to tank water temperature.
Small ones aren't but big ones are as you get the water level low quickly small and often is better than big and further apart.


The trouble with a drip system is that some new water typically goes out with the old.
Drip systems somewhat flatten the bell shape curve of pollution buildup and slightly extend the duration before a necessary WC, but are not a good substitute long term.
Not if done correctly they are normally done on big tanks and the drip is at the opersite side to the waste besides once the new water mixes with the old it is all the same it dilutes the pollution, it doesn't stay seperate from rest of the water. Which tank has the freshest water a drip system that slowly changes 100% of the water twice a week with no manual water changes or a tank that has 25% water manually changed twice a week



The trouble is we can't really see how increased pollution is affecting the long term health of the stock. Folks that push it think their fish are just fine and live an average life span...but what if with increased water changes where the water is more pure caused the same fish to live twice as long?
This is where you have to observe the tank, the fish and do water tests and ye you would be correct there is more to it than nitrates. The point is there is a point where more water changes don't do anything it is finding where that point is that is the question. Unfortunatly so far there has been little to help find that point.
 

· Pixel Prestidigitator
Joined
·
4,339 Posts
Actually decreasing the amount of pollution in a tank with a partial water change is not stressful - it's like a rain in nature. When I do water changes the fish seem invigorated. But yes, the change water needs to at least be close to tank water temperature.
In many instances however the rainwater is actually cooler than the pond/lake/river water. In fact that cooler water can trigger some species to spawning.


Over the years I've experimented with different water change schedules on different tanks.
One I had on the back porch was a dirt tank planted with livebearers. Never did a change on it. The plants thrived for a while and slowly died. Started doing water changes and many came back.
I've tried weekly changes and that is what I currently do on many of the tanks I run. Fish are doing well. So are the plants. But I do at least a 50% change.
In my breeding tanks I change at least once a week. Usually 2.
In my fry tanks I change every day. I've experimented with frequency of changes on fry tanks and I have found over the years I can get fry to a sellable size faster with the daily changes.

Those are just my results, with the fish and plants I raise, and the well water I use. Your results may or may not be the same and no one answer is right for all of us.

I also do do a fish in cycle. When I actually cycle a tank that is. I've found with well water cycling a tank isn't all that necessary. I can, and do, literally fill a tank and add fish with no loss whatsoever. Turns out many in my area do the same thing.

Bump:
Small ones aren't but big ones are as you get the water level low quickly small and often is better than big and further apart.



Not if done correctly they are normally done on big tanks and the drip is at the opersite side to the waste besides once the new water mixes with the old it is all the same it dilutes the pollution, it doesn't stay seperate from rest of the water. Which tank has the freshest water a drip system that slowly changes 100% of the water twice a week with no manual water changes or a tank that has 25% water manually changed twice a week





This is where you have to observe the tank, the fish and do water tests and ye you would be correct there is more to it than nitrates. The point is there is a point where more water changes don't do anything it is finding where that point is that is the question. Unfortunatly so far there has been little to help find that point.
There are breeders down here that change 100% of the water once a week. In nature large water changes do happen.


Auto change systems are great. I am designing one to handle the tanks I am running. But there is no substitute for getting the muck out of the substrate with a gravel vac. If you have substrate. I have bare bottom so I do siphon the mulm once ea week by hand.

The only way you will ever find out the frequency and amount of water YOU need to change is to experiment and see. I know what works for me and for what I am trying to accomplish. It's also not about keeping the fish alive. It's about keeping the fish thriving. There is a difference.

If you just add tap water as make up water you are increasing your TDS. Maybe need to look at RO for make up water.
 
1 - 20 of 173 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top